.. Weather Update #1 ..

NWS watches/advisories/warnings that have been issued as of 355pm CT:

NWS/Austin-San Antonio… None issued at this time for our local area.

NWS/San Angelo… a WINTER WEATHER ADVISORY will be in effect for Mason County
from 6pm Thursday evening to 12 noon Friday for possible ice/sleet accumulations of 1/10th
to 1/4 inch.

NWS/Fort Worth… a WINTER STORM WARNING will be in effect 12 noon Thursday until
6pm Friday for areas northwest of a line from Goldthwaite to Canton line for the likelihood
of significant ice/sleet accumulations (1/4 to 1/2 inch ice/sleet accumulations)
with downed trees and power lines possible with lengthy power outages possible.
A WINTER WEATHER ADVISORY will be in effect 6am Friday until 6pm Friday
for the area southeast of the warning above and to include Bell and McLennan counties.. including
the Killeen.. Belton.. Temple and Waco areas for the possibility of ice/sleet accumulations of less
than 1/4 inch.

DISCUSSION

Another very cold arctic air mass is sliding southward out of Canada into the western half of
the USA. Temperatures earlier today back in the heart of the surface high pressure area in
western Canada were as low as -31 degrees F. As this cold air continues to move southeastward
into Texas, it, as usual, will be in a relative shallow layer close to the ground. This will combine
with an active subtropical jet stream to cause moisture to overrun the cold air and then upper air
disturbances embedded in the subtropical jet stream to move by between now and Sunday, create
lift in the atmosphere and, as a result, cause precipitation.

The front will arrive in the Austin area tomorrow morning with rain showers and light rain and temperatures
falling from around 60 degrees F to the 40s by afternoon with a gusty north wind. Tomorrow night’s/Friday
morning lows will be around freezing with temperatures holding in the 30s.. and potentially below freezing..
into Saturday night and early Sunday.

Again, with this episode, please understand that precipitation will occur.. especially early tomorrow
into Saturday. The surface temperatures and the temperature of the air aloft in the shallow layer of
cold air will either “break us” or “make us” as far as the prospect of getting rain or the possibility of
getting freezing or frozen precipitation. In comparison with the cold air outbreak and precipitation one
to two weeks ago, I think this air mass looks to be colder.

Unfortunately, it may be more “last minute” as whether we have potential effects from this system..
we’ll need to watch the morning rush hour on Friday for the potential for freezing rain.. and, then again,
for Friday night into Saturday morning for the possibility. Another disturbance could give us a shot..
although it would appear at lower precipitation probabilities.. for the Saturday night into early Sunday
morning time period.

A quick important note to let you know of the potentially widespread and dangerous winter weather (ice storm)
situation that map develop to our north over north Texas, Oklahoma into adjoining Arkansas where
WINTER STORM and ICE STORM WARNINGS are already in effect. This could cause widespread
and long lasting power outages in north and northeast Texas.. including the Dallas/Fort Worth metroplex
as well as the Longview/Tyler/Kilgore as well as Texarkana areas over the coming days.

I’ll continue to monitor this situation.